using System;

namespace Org.BouncyCastle.Asn1.X509
{
    /**
     * <code>UserNotice</code> class, used in
     * <code>CertificatePolicies</code> X509 extensions (in policy
     * qualifiers).
     * <pre>
     * UserNotice ::= Sequence {
     *      noticeRef        NoticeReference OPTIONAL,
     *      explicitText     DisplayText OPTIONAL}
     *
     * </pre>
     *
     * @see PolicyQualifierId
     * @see PolicyInformation
     */
    public class UserNotice
        : Asn1Encodable
    {
        internal NoticeReference	noticeRef;
        internal DisplayText		explicitText;

		/**
         * Creates a new <code>UserNotice</code> instance.
         *
         * @param noticeRef a <code>NoticeReference</code> value
         * @param explicitText a <code>DisplayText</code> value
         */
        public UserNotice(
            NoticeReference	noticeRef,
            DisplayText		explicitText)
        {
            this.noticeRef = noticeRef;
            this.explicitText = explicitText;
        }

		/**
         * Creates a new <code>UserNotice</code> instance.
         *
         * @param noticeRef a <code>NoticeReference</code> value
         * @param str the explicitText field as a string.
         */
        public UserNotice(
            NoticeReference	noticeRef,
            string			str)
        {
            this.noticeRef = noticeRef;
            this.explicitText = new DisplayText(str);
        }

		/**
		 * Creates a new <code>UserNotice</code> instance.
		 * <p>Useful from reconstructing a <code>UserNotice</code> instance
		 * from its encodable/encoded form.
		 *
		 * @param as an <code>ASN1Sequence</code> value obtained from either
		 * calling @{link toASN1Object()} for a <code>UserNotice</code>
		 * instance or from parsing it from a DER-encoded stream.</p>
		 */
		public UserNotice(
			Asn1Sequence seq)
		{
			if (seq.Count == 2)
			{
				noticeRef = NoticeReference.GetInstance(seq[0]);
				explicitText = DisplayText.GetInstance(seq[1]);
			}
			else if (seq.Count == 1)
			{
				if (seq[0].ToAsn1Object() is Asn1Sequence)
				{
					noticeRef = NoticeReference.GetInstance(seq[0]);
				}
				else
				{
					explicitText = DisplayText.GetInstance(seq[0]);
				}
			}
			else
			{
				throw new ArgumentException("Bad sequence size: " + seq.Count);
			}
        }

		public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector av = new Asn1EncodableVector();

			if (noticeRef != null)
            {
                av.Add(noticeRef);
            }

			if (explicitText != null)
            {
                av.Add(explicitText);
            }

			return new DerSequence(av);
        }
    }
}
